Dynamic bioabsorbable fastener for use in wound closure

Abstract

A fastener for insertion into pierced openings of a tissue wound has a body formed of a generally bioabsorbable polymer defining an initial capture area internal to the body. The body includes a pair of arms, each with an inwardly projecting cleat operably joined at an elbow portion defining an internal elbow angle. The arms are operably joined to a backspan at a shoulder portion defining an internal shoulder angle. A durable tissue retention zone is defined between the cleat and the arm. The elbow portion and the internal elbow angle define an insertion width greater than a width of the pierced openings resulting in the pierced openings stretching over the cleat and being elastically retained within the durable tissue retention zone. The fastener initially captures wound tissue in the initial capture area and then dynamically reforms in response to lateral stresses applied by the wound tissue without a fracture failure of the fastener until a minimum degradation period.

Description

RELATED APPLICATIONS AND PRIORITY CLAIM[0001]The present application is a continuation application of co-pending U.S. patent application Ser. No. 10 / 603,397, filed Jun. 25, 2003, entitled “DYNAMIC BIOABSORBABLE FASTENER FOR USE IN WOUND CLOSURE, ” which is a Continuation-in-Part of U.S. patent application Ser. No. 10 / 179,628, filed Jun. 25, 2002, now allowed in U.S. Pat. No. 6,726,705, entitled, “MECHANICAL METHOD AND APPARATUS FOR BILATERAL TISSUE FASTENING,” and co-pending U.S. Divisional application Ser. No. 10 / 448,838, filed May 30, 2003, entitled “MECHANICAL METHOD AND APPARATUS FOR BILATERAL TISSUE FASTENING,” all of which are herein incorporated by reference in their entirety.FIELD OF THE INVENTION[0002]The present invention relates generally to the field of surgical fasteners for use in wound closure. More particularly, the present invention relates to a design for a dynamic, bioabsorbable fastener designed for through-and-through insertion across a wound having a capacity t...

AI Technical Summary

Benefits of technology

[0013]First, the thermoplastic polymers used in typical bioabsorbable staples possess a viscoelastic quality or polymer creep when subjected to continuous stress loading due to the nature of their molecular level bonding and entanglements. Traditionally, bioabsorbable fastener designs have compensated for this creep by either thickening the backspans or staple legs to prevent or reduce the deformation of the staple, or adding retaining clips or latches to preclude such deformation. Instead of trying to counteract the viscoelastic qualities of the polymer, the present invention takes advantage of these properties to provide for a dynamic response to lateral tissue forces that can deform the fastener, but not so far that the cleats of the fastener would release the tissue in the durable tissue retention zone.

[0015]Finally, when fastening opposing sides of a wound, the opposing sides must be physically approximated during placement of the fastener. Once the opposing sides have been retainably fastened, the opposing sides tend to return to a more relaxed disposition during the healing process, thereby increasing lateral pressure on the bioabsorbable fastener. In conventional practice, the bioabsorbable fastener ends up being over-designed in order to assist in the initial approximation of the tissue that can result in a design that is more susceptible to failure as a result of the longer term lateral pressures applied during the wound healing process. In contrast, the bioabsorbable fastener of the present invention is designed for use with an insertion apparatus that mechanically approximates the opposing sides of wound tissue to insure the creation of consistent and repeatable pierced openings into which the fastener is positioned in a through-and-through manner to take advantage of elastically securing the tissue within the durable issue retention zones created by the cleats of the fastener.

Problems solved by technology

First, the thermoplastic polymers used in typical bioabsorbable staples possess a viscoelastic quality or polymer creep when subjected to continuous stress loading due to the nature of their molecular level bonding and entanglements.

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